SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cf66794688ad82149c5cf35bc3171a0945489e536ffe1680fe5d50d4f0163b4' 
  AND token = 'YGLYngsy0vfepz6gTXv7UWnUBird7Svv44zyrllU6EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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