SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3be6e214aff8d4c95a908a3cef3ba53ccac21ae4b416c5bb37ef85454964e813' 
  AND token = 'MRZYqWpADFgX/DNR8jeYP+K7lAUvjqH8X9TOFa834bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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