SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82c5cdfd09b375aa6f22aaaaa29998af861d6372340a47406b02f2014f27ddbd' 
  AND token = 'cdzpANyIkUGTfgr1YZmq8zuFK6oqI/Pyc9LsUROBbAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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