SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c2154e6f2e2dbef9aef25fd7b87e5b1006b8a832ada63a73691a54d477193d7' 
  AND token = 'dZPb4hB/Czm+7pkmqiSxAO3XU6HyuFSHGz/Oz/mFCcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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