SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c2cbd5db9ed915114d59e65579f2495948aaa56a3593189faef546b20b8c4f' 
  AND token = 'gcXNejpQcAjsidpfpJF/4GaORGVREBU7XIHakrodkLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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