SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '716557c9cb911a11770b5690fbd259db223715de45ae932dbef675b8cee91b71' 
  AND token = 'JI1u+W0ZIrVwAc+4RApg9qjdpwlkZWTmwkEPaXT6Sz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}