SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad080896ab2dada98d6dfa1111fc83f68b409a4ee534b081e858a61a1c47dfb' 
  AND token = 'GtnWISbTwkirM3udrgArsaK6wbA7sV1ywHdEnTg+syo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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