SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f390d96d0bca78657a11cbe5e7580b151ae6254908e28b314b61bfb32c7f714' 
  AND token = 'ZuoWnwx5+rAL3FybNwusHSvYF9n9eSU4rMbccVDQsvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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