SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd234782af47ae3c8ef17f498f500bc911dbed32809423325094658cfaa74042' 
  AND token = 'V/DBgOg0tBEbiEC4ZLSBZDndSBzxbjUUH1LeBFqn/9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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