SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fdd6bee3c894e050fdf9871734514453ff5a14b28af834cceb59aa1bf5a7e61' 
  AND token = 'tGrhGwz+F57XKD9LLo+wuxUTL/vDA1f/qfBbDCh3Yjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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