SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e6b6871df3eb83950526111ab1858c191cb0de1ac7a17377e8a26ccaf8f9230' 
  AND token = 'IMHPIj4gS0kWQj8Ifdd6Te/1tYKuucULsh1FGuJHaR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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