SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d6ce1ef34308f2c24eda65da82b1c51b9b142abf953dd154d475d42c8e2a102' 
  AND token = 'sA/VurgJ9aQR2DJJzJGalKo5Fcjab8L+U1EafVxr81U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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