SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65cb20e8e3cae93d5a7f9af0bdc8ca53360a6a570d84d7edbfb72939dfd58cda' 
  AND token = 'L+VGXLONYd6oBCqfEOe0PkKYkRt1hElf3RXiUdmVro4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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