SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08f66ea2bcf21e6061391aa01f0667ba1b3db4a2b8f32b121d4108865a14db0c' 
  AND token = 'mjN35u7NVKKIFjnlC5a1dITHJPtkYyO62Am7s8QKO+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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