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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90b3e1dc27d9410f5d191c14660c9efee28b4b5a30defcf4708ee9af3ffec826' 
  AND token = 'ceJ5XS3oxjDYHQvkb3aJW+NiaZnkwyk/Zt4vM1tpGPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}