SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a46214a28a0840f5793bdd3792622a360e8424dd35c472704567dbedbe382d40' 
  AND token = 'iSigSU2nlme9Kqfsu8ttUcZPCVFGH8X6AAAX76rTJvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}