SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e3040607d4a83530845470d2cf6bf5d3875fa8eb0adbad22bd8ccd262cad1ae' 
  AND token = 'Vg0fAgJhadQnglwmuVXOlrivxkCamQhXwLQosqT6VTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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