SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10c135bf624da30df1397631583d9030e73e5b058be56916310d29d913ad1db3' 
  AND token = 'Tk8Vv5rL/XuhscBNfYMMq8qfsUspYYpLPxrJ2AICdrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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