SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f8933924bf163579eff5c92455a2bc43c63f9a828c3b46316d81b737e99f0749' 
  AND token = 'fqvWYqj/oXtQ6/VjRjYgGj0g2PYfl5NsFRzN2ZfNZXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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