SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ccb3afc933b9e36f689689de82dde9fc8fd5b227cf47086bf91ce243d814c8f' 
  AND token = 'V68jMgS24TDk+il+4/vyYlaWLYTegcblZw3WiVSn4dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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