SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '633bdfa45545d53f74e05842b59239bd59200ff885879164b2df1a9d9f23934f' 
  AND token = 'OF2yHY3FvVRJezI+OB8NRQybxwrEiBy+a21KFXQlQRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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