SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f662e7fcf4cdee845fb09736665f5b0c1b6b03792e7264090950f2b213fd1ff9' 
  AND token = 'i03V/s+kzvJ39Yb/EVQBRhP05+oXAuLHLhBZB7wp7KI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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