SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bfb8122aea8250d9c3347c1e3c82631b97f38c44232800e7857cf4a8a1d5e4bf' 
  AND token = 'w8fpryPyZX1BIQ9en6Jk9UOjYBFTIBYqZrAxKo0ksXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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