SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c84e857259ce9dc56e3e99ff2f981161ecb17946936be3096fa01aaded588afb' 
  AND token = 'wuKVsUC4WMFMGrMCSqxoPs5zoHhfJjmTk1f5ks7Hhl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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