SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '930e65c8279abb328e7abef2194ff18c375a38d2ee18fbc5446d785c26ddb738' 
  AND token = 'XG+J6u7KkrBrzR3d6Sq0+Y73zt1MysswDbjbqTJCOzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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