SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1b47efdda3be7cd0b91926c5cdf8b3f8d108edb0ec81091324c32da3730e923' 
  AND token = '0sRtq0do/nmjoTcTzYZaoIJsYzGwzDjkharIWStnUsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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