SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ea18fe8ff91565576548afab06aa299d1c2db8948a8b9495b94aae5cd07c8d9' 
  AND token = 'XKh3DuwARB9EnnIckR/P8TsD4LycBTQEXESamVksugc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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