SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '007f7666c0231f1b500370976f50a87d02d9cde90870698257a7ab378d6ee212' 
  AND token = 'Ft9v+fTtEnsKTYh8f1YUi8AVC/NWZPlwlT06viEOnEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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