SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7758dea5be9477e2c578c66645e1daea2e095239f5d466cdd93cd542c8021086' 
  AND token = 'vyv66GspacS0Hy8DNsMUIWrP76JhZZ16VnRKQT2WS8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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