SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd319e1be4d5f75759a8ab90e001d5cdc313f95c15613ea5d84b8ad6467820ae9' 
  AND token = 'Jq1xgGDUgMqv/Uz4PkhDXV+DgCAlLcBV06z+/Y9MGrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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