SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81dca7315edef463476fa87ceff4fa932f5125cc9929c2eff3a5503adb7dc777' 
  AND token = 'e19SZF3XT7DzxQu3qM6A0U+I2qz8q/ZfIcjIKF3FoAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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