SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c69e99609ce9d619841a63004da5064c4c9031a27050aed833859eee9883ab98' 
  AND token = 'lOR/sPHHFwzkstKfRMs2HT1JtrYnzKlTtevpxwSxL+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}