SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63b09de4a23cf574fc44d9dafa125bf8816a5a296815689e579f3d5430b77e35' 
  AND token = 'qC7aGKfkDiPItaTzLFYdKRB7xtmSE5t9CwzzS2SiiO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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