SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd015fbb46c5403b3961f418a31e3602e960abc8b2a5793bb46e8a9356aac2721' 
  AND token = '8HnXsyO2tZNU4zVR/M6XszCUyiyp3K1j0gqMsJ9uFvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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