SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b77160c3bcc7da658cfa6e03e9c26e739c35526c7a09c6319d5efb24d8c24702' 
  AND token = '9vG5KSJxbUkCp+NNdSirymTTrgKMGJ4bSx4nS7kjbjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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