SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd6a53ec9df8fe24f953a1f4f6c0c2d344d445e6350cbf9e3143d7ff54c504f43' 
  AND token = '2lMVT/kFKhJ37q2w+JykrICtBAvJfQjgr0WT8wpS/uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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