SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17891f52465689d8043b10d1c19ce101b19563150e96949ef75d64a42ecc0851' 
  AND token = 'vD03UhmIl9EEReYzYKvrvTJLKtQUSafcq7+R6oBB9QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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