SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8008853642fc7bd7d5649fde1055ee31ef96fd2d8228e472ed1de7584e41a7b3' 
  AND token = '7hAdostHgmM9ocmx5FILbqOTDhWpwulY4hcrUsuIoIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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