SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8411a4fc8a5c0cec75b044b789a18a4325b57ea57337553635469fcd6695c154' 
  AND token = '8jfFjCctiTShvNK7HFGRVNchzazO04OI5XCYBHrU6mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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