SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7279a11faa58d6de0ab072f348ef9aa83dde833288a56ad905fdfe6f06403d1' 
  AND token = 'Nzt829c/DI4bkbAdcz/ch01o0m7KFM1rWsGgh+4XjtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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