SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acc10504f39760edc75f1face713ea9da65febdbaf0964551323b3a64d702e4e' 
  AND token = 'Kd09akX96B+sQ54Vf9YVdXuWPDkuQ+r16gfHhjU/WkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}