SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7b232b114aec237d671600d1f63112d30625bf7d9730259e551e131c91e480a' 
  AND token = 'Pn0wTFr7IBLiZCTUYUyTU+i5ZbEEAyB0Q7uApTVpZVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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