SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '237440b1b2ffcf7ebfe8ab1246b7c39a89ac8cf050a253d949bcbbb282bc5d44' 
  AND token = 'paEnnZku26GZJ/FdQtFUB8lLIySuQh91bEmJQCKDOz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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