SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a332cb38ecb75be1f2494f28266d133929465fea8e1172257ca24018789891f1' 
  AND token = '7fJyMKcSbjPC2GkthtYu3Cl2gOpwC882Nh0vjlbQNUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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