SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f474af5ed204a3cc5f48ae27011d37123c29c0a320047bcaa4719af4b82b9676' 
  AND token = 'XV4dwvu7YOX1ynIr58uwzkwqA4Ra4FyjH42L7EMZPzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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