SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37463303a254cdfd8042c5efa34149c26ab2e54138bda1b418b57ab1184bfab0' 
  AND token = 'jrDw+KjuiAdKckpTf0Hz9rvY7TBqRtft27aZiOVvn3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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