SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e17a499f0750b22335872be299d840d0d7bc4ada428492bcc0415dc85a9ec72b' 
  AND token = 'DlkIOV8bIge+BmUIVvG1eIvZSlVXFm5IP3UFPtAfJMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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