SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00457d8fa87bea2a5bc9f7fbe19b95fb1276db08633a972e7f6745a4a342955c' 
  AND token = 'yFOVgvs+GYtadzIANyJmC97zH+NLlY3VUSMNqETrdLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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