SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '624dc3224d858ba5ea68260e809244ad288d8f0bb8ae1e6ce597fa5ac754744c' 
  AND token = '8iy5NfATw8Kqr/pnIAmEO7AaZQ05SKmaeDUXL+afhnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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