SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '830d6ec71b78c89cb86e549e5589d1a385e510bcb8df26935e416f35e227a68d' 
  AND token = 'J+YFWFoEagYyq02TuBvhXvwzLDzaDHvDJFdDrEtDBwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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