SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b025ab048f406f10caafb862aa65f58fea89777b47db17adba5a910975323cf' 
  AND token = 'hXc0D8W+SlDrPIofgmJy8RBtnx3CtIrdjjbrT4T6oDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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