SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d43e213da6e7db134515fe627be941a55e484f2a1c78dcec357309d8f0ae86f' 
  AND token = '9dOwmhNVSjqY1BXQd1as/YZpW86rPIFZkLjIZIaDZAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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