SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2c0a2ca854b437df3930ad6964119641c8c85d586943c2e115e83af4abcdffb' 
  AND token = 'PTzTmVKlokbHNnxl547nzH0BgHredXtJUCoID49nQTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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