SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c834bcaaf8ee9e93b01efe35594979b6cd8c57b9ae2771197f001abd236edcf5' 
  AND token = 'lCjFRFrA5pftFucTQ1b+Yve3y8P/YeYNxZ6+/ANK4l0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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