SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24e0fd03ca7d2618a84a3ea8739c707640d142ba7dcd1037c1094aa09e117dbc' 
  AND token = 'Ewgt8XM+B2yf4O+t5+STb15StPCjxbaogXoUE/zqTZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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