SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24dd159ace119e115b9358087fe531a3a768712e7ac283d13cd291084bff1557' 
  AND token = 'JhPcLA46eYsJ9ZyN+PrFUAk5snS8VAw44iDL1vDGILA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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