SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d658bb516b3b1affa78cd7ced99432a60728957ef9baf51acf8b53b1679118a' 
  AND token = '6V8icHGtEv1AbMzhD533QroCH9IdAGkbnDtNEHUeKoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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