SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '373081b2391ce347d1ab88d012339c961a6ea54743144680d9f80c87d2f645e5' 
  AND token = 'pkfd+72j54KnuvnR1eBBNhiWvPmUTsW14FKNeKeVS1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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