SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4df073db6b297c9977228fba6714044981452415de9671bfed65dee532d92ab3' 
  AND token = 'OFkTFZzzJHhhErsVZF1KCbiyJhqHKFt4Qnjz30NQ47w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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