SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '742a4c0fe3165a24564751eed7f13b77f1a9b0ad93935dbab8ae6cb60383086b' 
  AND token = '7hei2Ke8vMoQGnERzKG3HfHYjB7DvA6RsF8ssRQoR1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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