SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79d26d91cbaef65bad1c93f81a01a7d723b8e646aaedcbd2be65a6aa9f95dc4c' 
  AND token = 'IJzZCVY01HhMyoKQ5DOu9E+p+xs53ujC5MZRGclh1Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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