SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd748bcde6f69e923e03d7642724a57038b969a5a4ae680f7b5c8098142b75fac' 
  AND token = 'Vp74LBELpdl2ycUEcMKjJqz6YC20MDkPiZMprYNOJZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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