SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcda39c2070db0695ca0621c9fd7e7073b857d212500ad2a6c1486221404df33' 
  AND token = 'RibsQCMUYtYYMhGv8HoqkVdwmfBfHQQP3PdddTl5GNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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