SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4929fc9b66dd814edf56316750904334bd5997c19a9b8bfafc6feb49048ae6dd' 
  AND token = 'iPt1uGOisXx7qPjNdG161noLTYpM0wr3UIjWJZbwiJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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