SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fdd8e2f079f307b8bb80da0a073d04ccd9099e5e13135bfd6d956a3a4716116' 
  AND token = 'R23iHOMPk1fOIIyiePd/ch2WqPGSJPvPviRPjxnX9CE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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