SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3985fe0464504f302aea16d5c297295df56ec44a199da58de599833dfb0eac09' 
  AND token = 'taFnqNnPawPeW7LUdn6I/RFJrcz/lN6r40xh5+BTaNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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