SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfee5bfaf4fe9bb676705b77de39a3f6219a73992fcbef8ec1facd99307a11e4' 
  AND token = 'rM4l6WxoxSajZ1QlQ26HlMuVD53kIjBNTzEeQJLTebg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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