SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'add5459719ec9f88eb38551cdba463bbf70ae1db486e87e025e553509b54f300' 
  AND token = '/iHOPwPPAFe1gQ4dQrNldSjDoDXBjCkFisihwppIO2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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